GCr15
seamless steel pipe is a high carbon chromium bearing steel with less alloy content, good performance and wide application. After quenching and tempering, it has high and uniform hardness, good wear resistance and high contact fatigue performance. The cold working of the steel is medium in plasticity, the cutting performance is general, the welding performance is poor, the sensitivity to white spots is large, and the temper brittleness is obtained.
Chemical composition / element content (%)
C: 0.95-1.05
Mn: 0.20-0.40
Si: 0.15-0.35
S:<=0.020
P:<=0.027
Cr: 1.30-1.65
The heat treatment system is: steel bar annealing, wire annealing or 830-840 degree oil quenching.
Heat treatment process parameters:
1. Ordinary annealing: 790-810 degrees heating, after the furnace is cooled to 650 degrees, air cooling - HB170-207
2. Isothermal annealing: 790-810 degrees heating, 710-720 degrees isothermal, air cooling - HB207-229
3. Normal fire: 900-920 degrees heating, air cooling - HB270-390
4. High temperature tempering: 650-700 degrees heating, air cooling - HB229-285
5. Quenching: 860 degrees heating, oil quenching - HRC62-66
6. Low temperature tempering: 150-170 degrees tempering, air cooling - HRC61-66
7. Carbonitriding: 820-830 degrees osmosis 1.5-3 hours, oil quenching, -60 degrees to -70 degrees cryogenic treatment +150 degrees to +160 tempering, air cooling - HRC ≈ 67
